<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

    <script src="./jquery-3.6.0.min.js"></script>
    <script type="text/javascript">
        $(function() {
            //alert($('#form1 :text').length);
            //alert($('#form1 :password').length);
            //alert($('#form1 :radio').length);
            //alert($('#form1 :checkbox').length);
            //alert($('#form1 :submit').length);
            alert($('#form1 :input').length);
            alert($('#form1 input').length);
        });
    </script>



</head>

<body>
    <form id="form1" action="#">
        <input type="button" value="Button" /><br/>
        <input type="checkbox" name="c" />1<input type="checkbox" name="c" />2<input type="checkbox" name="c" />3<br/>
        <input type="file" /><br/>
        <input type="hidden" />
        <div style="display:none">test</div><br/>
        <input type="password" /><br/>
        <input type="radio" name="a" />1<input type="radio" name="a" />2<br/>
        <input type="reset" /><br/>
        <input type="submit" value="提交" /><br/>
        <input type="text" /><br/>
        <select><option>Option</option></select><br/>
        <textarea rows="5" cols="20"></textarea><br/>
        <button>Button</button><br/>
    </form>

    <div></div>
</body>

</html>